Both myself and my wife went through the music college system and worked as pro musicians, when we got married and had children we decided one of us needed to give it up so as to be around for the boys. We both ended up becoming teachers, my wife still teaches flute and earns around £30 an hour privately and about £35 an hour at a local independant school but her annual income is pathetic for the level of skill she has and the years of training/performing she did (from age 7 to 50), this is due to the amount of hours you can teach effectively for, which in our opinion is no more than 25.
If you are teaching in schools then you only have 36 weeks a year to earn your living!
I became a classroom teacher and have since moved from teaching music to become in charge of outdoor education at a EBD school and have a reasonable salary – there is no way I would advise anyone to become a freelance instrumental teacher due to way both parents and schools will treat you – like sh1t!